Absorbent fibrous structures comprised of low strength absorbent materials such as airlaid wood pulp fibers are well known in the disposable absorbent bandage art. In certain of these prior art fibrous pad structures it has been found desirable to employ one or more internally located plies of tissue paper or other web materials which are substantially impervious to the passage of fibers to act, for example, as a reinforcing agent, as a fluid baffle to distribute absorbed fluids within the absorbent fluff structure, as a partitioning agent of the like. Addition of such internal plies which have a width substantially equal to that of the absorbent fibrous webs located on the uppermost and lowermost surfaces thereof has typically been provided by utilizing a multiplicity of discrete forming zones with a separate fiber supply source for each zone. However, the multiple forming zone approach typically employed by such prior art systems requires considerable converting line space and involves a duplication of disintegrating and air laying equipment for each absorbent fibrous layer employed in the resultant structure. Furthermore, altering the position of the internal ply relative to the uppermost and lowermost surface of the finished absorbent pad typically requires a complex adjustment procedure for each fiber deposition zone in the system.
Accordingly, it is an object of the present invention to provide method and apparatus for forming an airlaid fibrous fluff web adjacent the uppermost and lowermost surfaces of a substantially planar, fiber-impervious internal reinforcing ply having sustantially the same width as said fibrous web in a continuous fiber deposition zone.
It is another object of the present invention to provide method and apparatus for easily altering the position of the internal reinforcing ply relative to the uppermost and lowermost surfaces of the absorbent web in question.
It is yet another object of the present invention to provide method and apparatus for forming an airlaid fibrous fluff web adjacent the uppermost and lowermost surfaces of a substantially planar, fiber-impervious, internal reinforcing ply having substantially the same width as said fibrous web in a continuous fiber deposition zone having an overall length no greater than that required to form an identical absorbent web of comparable basis weight without said internal reinforcing ply.